Intraocular surgical apparatus

ABSTRACT

An intraocular surgical apparatus is disclosed. The appartus includes an introduction tube for introducing perfusate into a closed intraocular affected part, a discharge tube for discharging the affected part together with the perfusate, a perfusate feed passage connected to the introduction tube, the perfusate feed passage incorporating a perfusate reservoir capable of feeding the perfusate with a predetermined rest liquid head pressure and a control valve for controlling the amount of perfusate to be fed from the perfusate reservoir to the introduction tube, and a. discharge passage connected to the discharge tube, the discharge passage incorporating a suction pump. The perfusate feed passage further incorporates, at a passage portion thereof from the control valve to an outlet opening of the introduction tube, a pressure-reduction compensating means capable of feeding a supplementary amount of perfusate into the closed intraocular affected part through a supplementing passage having a smaller passage resistance than the perfusate feed passage in the event of and in association with abnormal pressure reduction inside the affected part.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an intraocular surgical apparatus for use in a surgical operation for treating e.g., cataracta.

[0003] 1. Description of the Related Art

[0004] In recent years, for treatment of eye diseases such as cataracta, a surgical operation is often carried out for replacing the affected crystalline lens in the eye of the subject by an intraocular lens (artificial crystalline lens). In this respect, as an operation for extirpating such affected part as the crystalline lens, there is known the ultrasonic emulsifying aspirating operation (KPE) for applying ultrasonic waves to the affected part, e.g. crystalline lens, for pulverizing (emulsifying) it and, at the same time, aspirating and discharging the pulverized part to the outside.

[0005] A typical apparatus for use in such ultrasonic emulsifying aspirating operation described above, as shown in FIG. 4, includes a handpiece 3 having an introduction tube 1 for introducing perfusate (artificial aqueous humor) C into the closed intraocular affected part B and a discharge tube 2 for discharging the emulsified affected part together with the perfusate C. A perfusate feed passage D connected to the introduction tube 1 incorporates a perfusate reservoir E capable of feeding the perfusate C with a predetermined rest liquid head pressure (h). A discharge passage G connected to the discharge tube 2 of the handpiece 3 incorporates a suction pump H for controlling operation of a switch valve F of the feed passage D to open the valve F in association with an aspirating operation or to close it in association with stopping of the aspirating operation.

[0006] With such construction above in operation, an outlet opening 1B of the introduction tube 1 and an aspiration opening 2A of the discharge tube 2 of the handpiece 3 are inserted together into the closed intraocular affected part B through a small access incision made in the cornea or sclera of the eye to be treated.

[0007] Then, ultrasonic waves are applied to its affected part such as crystalline lens for its gradual emulsification and at the same time the emulsified part is aspirated and discharged to the outside by the suction force of the suction pump H. In the course of this, the switch valve F incorporated in the perfusate feed passage D is opened in response to the operation of the suction pump H so as to introduce, in association with the sucking action of the pump, fresh perfusate C in an amount corresponding to that aspirated and discharged from the perfusate reservoir E into the intraocular affected part B via the introduction tube 1, thereby to balance between the flow rate of perfusate and the suction force of the suction pump.

[0008] However, as illustrated in FIG. 5, it sometimes happens that the introduced part may be momentarily stuck at the aspiration opening 2A of the discharge tube 2 and then suddenly released therefrom to be drawn toward the discharging side.

[0009] In the case of such excessive aspiration phenomenon as above, because the perfusate feed passage D provides certain passage resistance and the outflow rate of the perfusate C from the outlet opening 1B of the introduction tube 1 is fixedly governed by the effect of free-fall, the balance between the inflow amount from the introduction tube 1 and the outflow or discharge amount from the discharge tube 2 is lost, with the latter exceeding the former. This leads to momentary abnormal pressure reduction and development of negative pressure within the closed intraocular affected part B compared with a normal pressure in the case of a normal operation, so that the negative pressure may result in a so-called micro-collapse phenomenon characterized by reduction in the content volume of the eye or anterior chamber. In an extreme case, such micro-collapse phenomenon may result in rupture of the posterior capsule or damage in the endothelium camerae anteioris.

[0010] Customarily, when a surgeon notices the possibility of such phenomenon above, he/she will expediently adjust the amount of ultrasonic waves and/or the aspiration amount in such a manner to avoid it. However, in order for the surgeon to be able to do so, he/she needs good amount of practice using animal or artificial eyes for training as well as considerable amount of actual experience in the surgery.

SUMMARY OF THE INVENTION

[0011] The present invention has been made in view of the above-described state of the art. The primary object of the invention is to provide an improved intraocular surgical apparatus which effectively prevents occurrence of micro-collapse phenomenon in the eyeball and the anterior chamber in the event of such abnormal pressure reduction in the closed intraocular affected part due to momentary clogging of the affected part at e.g., the inlet opening of the discharge tube and subsequent sudden movement thereof toward the discharging side.

[0012] For fulfilling the above-noted object, according to one aspect of the present invention, there is provided an intraocular surgical apparatus comprising:

[0013] an introduction tube for introducing perfusate into a closed intraocular affected part;

[0014] a discharge tube for discharging the affected part together with the perfusate;

[0015] a perfusate feed passage connected to the introduction tube, the perfusate feed passage incorporating a perfusate reservoir capable of feeding the perfusate with a predetermined rest liquid head pressure and a control valve for controlling the amount of perfusate to be fed from the perfusate reservoir to the introduction tube;

[0016] a. discharge passage connected to the discharge tube, the discharge passage incorporating a suction pump;

[0017] wherein the perfusate feed passage further incorporates, at a passage portion thereof from the control valve to an outlet opening of the introduction tube, a pressure-reduction compensating means capable of feeding a supplementary amount of perfusate into the closed intraocular affected part through a supplementing passage having a smaller passage resistance than the perfusate feed passage in the event of and in association with abnormal pressure reduction inside the affected part.

[0018] With the above-described construction, in the event of abnormal pressure reduction in the closed intraocular affected part due to momentary clogging of the affected part at e.g., the inlet opening of the discharge tube and subsequent sudden release and movement thereof toward the discharging side, in operative association with this pressure reduction, the pressure-reduction compensating means can supply, through the supplementing passage, a supplementary amount of perfusate to the affected part in order to compensate for the pressure reduction. Accordingly, occurrence of micro collapse in the eyeball and the anterior chamber can be effectively prevented, so that the surgical operation may take place in a safe and reliable manner.

[0019] In the above construction, the pressure-reduction compensating means is provided midway the perfusate feed passage. In this regard, since the passage resistance becomes smaller closer to the inlet opening of the discharge tube, it is preferred that the pressure-reduction compensating means be provided at a position near the inlet opening of the discharge tube. It is also to be noted that the control valve incorporated within the perfusate feed passage can be a variable flow control valve instead of a switch valve.

[0020] According to one preferred embodiment of the present invention, the pressure-reduction compensating means includes a supplementary perfusate reservoir storing a portion of the perfusate flowing within the perfusate feed passage and acting as the supplementing passage and a gas reservoir for reserving gas compressed under the predetermined rest liquid head pressure of the perfusate reservoir.

[0021] With the above construction, in the event of abnormal pressure reduction in the closed intraocular affected part due to momentary clogging of the affected part at e.g., the inlet opening of the discharge tube and subsequent sudden release and movement thereof toward the discharging side, in association with this reduction, there occurs expansion of the gas reserved in the gas reservoir under the compressed state, which expansion causes immediate reverse flow of the perfusate portion in the supplementing perfusate reservoir, as the supplementing passage of the pressure-reduction compensating means having the smaller passage resistance than the perfusate feed passage, into the intraocular affected part. Therefore, the construction with this additional feature can prevent occurrence of micro-collapse phenomenon in the eyeball and the anterior chamber more reliably and can ensure even more reliable and safer surgical operation.

[0022] According to a further preferred embodiment of the invention, the introduction tube and the discharge tube are provided in a handpiece which includes an ultrasonic-wave generating means capable of applying ultrasonic waves in focus onto vicinity of the inlet opening of the discharge tube.

[0023] With the above feature, when the affected part is emulsified with the ultrasonic waves and this emulsified part is discharged together with the perfusate, in the event of abnormal pressure reduction in the closed intraocular affected part due to momentary clogging of the affected part at e.g., the inlet opening of the discharge tube and subsequent sudden release and movement thereof toward the discharging side. Then, in association with or being triggered by this pressure reduction, there occurs expansion of the gas reserved in the gas reservoir under the compressed state, which expansion causes immediate reverse flow of the perfusate portion in the supplementing perfusate reservoir, as the supplementing passage of the pressure-reduction compensating means having the smaller passage resistance than the perfusate feed passage, into the intraocular affected part. Therefore, the construction with this additional feature can prevent occurrence of micro-collapse in the eyeball and the anterior chamber more reliably. Hence, this construction can be employed in e.g., the ultrasonic emulsifying aspirating operation (KPE) for significantly improving its safety and reliability.

[0024] According to a still further preferred embodiment of the invention, the supplementary perfusate reservoir and the gas reservoir of the pressure-reduction compensating means are constructed in the form of a single flexible continuous tube.

[0025] The above construction can improve the maneuverability of the apparatus not to interfere with the surgical operation and can improve also the handling of the apparatus. Moreover, the construction facilitates attachment of the pressure-reduction compensating means to an existing system such as a system used for the ultrasonic emulsifying aspirating operation. Because, this attachment requires only a minor modification of the system, such as use of a connector, e.g., a branch-tube joint, capable of connecting the discharge passage and the pressure-reduction compensating means. The readiness of the attachment will contribute to widespread use of the apparatus of the invention.

[0026] According to a still further embodiment of the invention, the flexible tube constituting the supplementary perfusate reservoir and the gas reservoir of the pressure-reduction compensating means is made of silicone.

[0027] Silicone material has the advantage of high resistance against chemical influence. Silicone is advantageous also in that it can be reused after e.g. sterilization. Moreover, if this silicone is of a translucent type, then, the translucence provides visibility of the supplementary perfusate reservoir and the gas reservoir disposed inside from the outside, thus facilitating preparation for a surgical operation. Further, if a mark is provided between the supplementary perfusate reservoir and the gas reservoir, this will help accuracy in the preparation, thus further improving the handling of the apparatus.

[0028] According to a still further preferred embodiment of the invention, the tube constituting the supplementary perfusate reservoir and the gas reservoir of the pressure-reduction compensating means is detachably connected and communicated with the perfusate feed passage connected to the introduction tube.

[0029] With the above feature, the detachability of the tube facilitates the assembly and putting-back of the apparatus for storage after its use. The detachability facilitates also sterilization and replacement of the apparatus or its parts when needed. Furthermore, by detaching the tube and then attaching a plug instead, any other conventional surgical operation can be effected also. In this manner, different intraocular surgical apparatuses may be used interchangeably, depending on the need.

[0030] According to a still further preferred embodiment of the invention, the tube constituting tube constituting the supplementary perfusate reservoir and the gas reservoir of the pressure-reduction compensating means has an inner diameter substantially equal to that of a tube constituting the perfusate feed passage.

[0031] With the above feature, the following advantage may be obtained. If one of the tubes has a diameter different from, i.e., greater or smaller than, that of the other, the perfusate will flow from the large-diameter tube into the small-diameter tube, hence providing a resistance at the transition region. Then, by using the tubes of an equal diameter not providing such resistance, the apparatus can cope with the pressure variation, i.e. reduction from the normal pressure at the time of normal operation, in the closed intraocular affected part, in a more reliable and speedy manner.

[0032] According to a still further feature of the invention, the gas reservoir of the pressure-reduction compensating means is charged with inert gas.

[0033] With the above feature, the supplementing perfusate reservoir is placed in contact with non-reactive gas atmosphere allowing sterilization. Then, this will further add to the reliability and the safety of the surgical operation.

[0034] Further and other objects, features and advantages of the invention will become apparent from the following detailed description of the preferred embodiments thereof with reference to the accompanying drawings.

BRIEFF DESCRIPTION OF THE DRAWINGS

[0035]FIG. 1 is a view showing an intraocular surgical apparatus according to one preferred embodiment of the present invention for illustrating its operational principle,

[0036]FIG. 2 is a view showing principal portions of the intraocular surgical apparatus for also illustrating its operational principle,

[0037]FIG. 3 is an enlarged section showing conditions of the principal portions of the intraocular surgical apparatus,

[0038]FIG. 4 is a view showing the intraocular surgical apparatus according to the prior art for illustrating its operational principle, and

[0039]FIG. 5 is an enlarged section showing conditions of principal portions of the conventional apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] [First Embodiment]

[0041] FIGS. 1-3 show an intraocular surgical apparatus according to one preferred embodiment of the present invention.

[0042] As shown in FIG. 1, this apparatus A includes a handpiece 3 having an introduction tube 1 for introducing perfusate (artificial aqueous humor) C into the closed intraocular affected part B and a discharge tube 2 for discharging the affected part together with the perfusate C. A perfusate feed passage D connected to the introduction tube 1 incorporates a perfusate reservoir E capable of feeding the perfusate C with a predetermined rest liquid head pressure (h). A discharge passage G connected to the discharge tube 2 of the handpiece 3 incorporates a suction pump H for controlling operation of a switch valve F of the feed passage D to open the valve F in association with an aspirating operation or to close the valve F in association with stopping of the aspirating operation. The apparatus further includes a pressure-reduction compensating means J consisting essentially of a supplementary perfusate reservoir J1 storing a portion C1 of the perfusate C flowing within the perfusate feed passage and acting as a supplementing passage and a gas reservoir J2 for reserving gas compressed under a predetermined rest liquid head pressure (h) of the perfusate reservoir E. In operation, the pressure-reduction compensating means J is capable of feeding a supplementary amount of perfusate C1 from the supplementary perfusate reservoir J1 to the inside of a closed intraocular affected part through the supplementing passage having a smaller passage resistance than the perfusate feed passage D in the event of and in association with occurrence of abnormal pressure reduction inside the affected part.

[0043] The introduction tube 1 includes a perfusate tip 1 a forming an outlet opening 1B at the leading end of a grip portion 3A of the handpiece 3, a receiver tube portion 1 b for detachably receiving the perfusate tip 1 a and a junction tube portion 1 c communicated with the receiver tube portion 1 b and formed continuously along a lateral face of the grip portion 3A of the handpiece 3. Further, the introduction tube 1 defines, at the rear end thereof, an inlet opening 1A connectable-with the perfusate feed passage D for communication therewith.

[0044] The discharge tube 2, in the form of a capillary coaxial with the perfusate tip 1 a of the introduction tube 1, is disposed inside through the handpiece 3, such that an aspiration opening 2A defined at the leading end thereof is disposed at a position slightly projecting from the outlet opening 1B of the perfusate tip 1 a and a connecting outlet 2B defined at the leading end thereof is disposed at a position projecting from the rear end of the handpiece 3 to be connectable with the discharge passage G for establishing communication therewith.

[0045] The aspiration opening 2A at the leading end of the discharge tube 2 constitutes an “aspirating port”.

[0046] The specific shapes and/or configurations of the perfusate tip 1 a of the introduction tube 1 and the aspirating port of the discharge tube 2 can vary in many ways, depending on the aspiration procedure, type of surgical operation, location of use, object of the aspiration discharge, preference of the surgeon, etc. For instance, the outlet opening 1B of the perfusate tip 1 a can be formed in a direction normal to the introducing direction into the discharge tube 2. Further, the cutoff angle of the aspiration opening 2A of the discharge tube 2 for acting as the aspirating port can be varied in many ways.

[0047] The grip portion 3A of the handpiece 3 accommodates therein an oscillating device, a focusing device, etc. These devices are connected via a cable 6 with a circuitry (not shown) including an output control unit, a power unit, etc. disposed outside, so that the devices together constitute an “ultrasonic wave generating means 4”. This ultrasonic wave generating means 4 is constructed so that ultrasonic waves therefrom are focused at the axial position of the aspiration opening 2A of the discharge tube 2.

[0048] The perfusate feed passage D is formed by a flexible tube 5 made of silicone. A base end portion 5A of this tube 5 is connected and communicated with the inlet opening 1A of the introduction tube 1. Further, a leading end 5B of the tube 5 is connected and communicated with the perfusate reservoir E which is filled with the perfusate C and disposed at a position of a predetermined adjustable altitude from a predetermined maneuvering position of the handpiece 3, so that with establishment of connection/communication between the perfusate reservoir E and the leading end 5B of the tube 5, the perfusate C can be fed to the introduction tube 1 with a predetermined rest liquid head pressure (h).

[0049] The altitude of the perfusate reservoir E is adjustable from 65 cm to 75 cm approximately from the position of the intraocular affected part B of the patient to be treated.

[0050] The perfusate reservoir E is provided in the form of a single glass or vial which is filled with the perfusate C prepared by diluting a predetermined drug solution with diluent More particularly, this perfusate C can be the commercially available “BSS-Plus” (registered trademark) which is a preparation made by diluting oxyglutathione solution with diluent by a predetermined dilution ratio.

[0051] Further, the switch valve F incorporated within the flexible tube 5 constituting the perfusate feed passage D comprises. e.g. a pinch valve which is a control valve capable of controlling the flow rate of the perfusate C depending on whether the valve F is fully opened or closed. A control scheme is provided for closing this switch valve F of the perfusate feed passage D in response to and in operative association with the sucking operation of the suction pump H and closing the valve F in response to stop of the suction operation by the suction pump H. More particularly, this control scheme is based on detection by a pressure sensor provided within the discharge passage G or detection of ON/OFF state of a pump driving motor for driving the suction pump H. In addition to the pinch valve, the switch valve F may alternatively comprises an electromagnetic type switch valve, a spring-loaded switch valve, etc.

[0052] The discharge passage G is formed by a flexible tube 7 made of silicone. A base end portion 7A of this tube 7 is connected and communicated with the outlet opening 2B of the discharge tube 2. Whereas, a leading end 7B of the tube 7 is connected with the suction pump H so as to allow suction in the discharge tube 2.

[0053] The suction pump H can be a peristaltic pump, venturi pump, diaphragm pump, etc. These types of pumps differ in the respect of e.g. rising speed up to a predetermined suction pressure. Among them, the peristaltic pump is particularly preferred, which is capable of rising its suction pressure from a basic suction pressure and which allows individual or independent settings of the suction pressure and the flow rate thereof. With this type of suction pump, its suction pressure can be increased or decreased in a controllable manner by increasing or decreasing the rotational speed of the pump driving motor for driving it.

[0054] In the case of the peristaltic pump, the suction amount will be about 0-44 cc/min., suction pressure will be about 0-500 mmHg; and the outer diameter of the outlet opening 1B formed at the leading end of the introduction tube 1 will be about 1 mm, and the outer diameter of the aspiration opening 2A of the discharge tube 2 will be about 0.3 mm, respectively.

[0055] For adjustments of the oscillation or generation amount of the ultrasonic waves by the ultrasonic wave generating means 4 and the suction pressure of the suction pump H, these adjustments can be made by means of a foot switch (not shown) operable to activate and cause the generating means or the pump to be shifted from an initial value to a predetermined higher value upon an operator's stepping on it and to deactivate it upon release of the foot therefrom. Alternatively, it can be operated in a continuously variable, i.e. proportional, manner depending on the “step-on depth” or amount of the stepping-on operation.

[0056] The pressure-reduction compensating means J is formed mainly of a flexible tube 8 of silicone. Its base end 8A is branch-connected via a branch-joint tube to the inlet opening 1A of the introduction tube 1 and its leading end 8B is closed by being damped by a clamp 9 acting as opening/closing means. Hence, within this tube 8, there are formed the supplementary perfusate reservoir J1 storing a portion C1 of the perfusate C and the gas reservoir J2 for reserving gas compressed under the predetermined rest liquid head pressure (h) of the perfusate reservoir E. In this, the supplementary perfusate reservoir J2 is formed by the introduction tube 1 in corporation with the other portion of the tube 8 than the gas reservoir J2. The perfusate portion reserved within this reservoir is referred to as the supplementary perfusate C1.

[0057] The leading end 8B of the tube 8 is to be disposed above the maneuvering area of the handpiece 3 and also below the set height of the perfusate reservoir E so as to ensure the formation of the supplementary perfusate reservoir J1 and the gas reservoir J2 inside the tube 8.

[0058] Further, for closing the leading end 8B of the tube 8, instead of the clamp 9 described above, a manual operation type switch valve can be attached. Or, a plug may be detachably attached.

[0059] In this embodiment, the tube 5 forming the perfusate feed passage D, the tube 7 forming the discharge passage G and the tube 8 forming the pressure-reduction compensating means J have an equal inner diameter.

[0060] Between the perfusate feed passage D and the discharge passage G, there is connected a bypass passage L incorporating a bypass switch valve K.

[0061] Then, when needed, by opening the bypass switch valve K and closing the switch valve F of the perfusate feed passage D and deactivating the suction pump H, reverse flow of the perfusate C is allowed from the aspiration opening 2A of the discharge tube 2. Further, depending on the necessity, by opening the bypass switch valve K, closing the switch valve F and then activating the suction pump H, any perfusate C remaining in the perfusate reservoir E may be forcibly discharged.

[0062] With the above-described construction in operation, first, in the initial empty condition of the tube 8 with the switch valve F of the perfusate feed passage D and the bypass switch valve K both closed, the leading end of this empty tube 8 will be closed by the opening/closing means 9.

[0063] Next, the switch valve F of the perfusate feed passage D is opened to allow the perfusate C to be released from the inlet opening 1A of the introduction tube 1 at the predetermined rest liquid head pressure (h). Under this condition, the leading end of the handpiece 3 will be sealingly closed with a plug (not shown), so that the inlet opening 1A of the introduction tube 1 and the aspiration opening 2A of the discharge tube 2 will be accommodated within the closed space filled with the perfusate C.

[0064] And, in this condition, with the introduction of the perfusate via the tube 5 into the tube 8, there are formed within the latter, the supplementary perfusate reservoir J1 and the gas reservoir J2 formed upwardly thereof for reserving gas 10 compressed under the effect of the predetermined rest liquid head pressure (h) of the perfusate reservoir E. Whereas, the portion of the tube 5 extending from the perfusate reservoir E and accommodating the perfusate C therein forms the perfusate feed passage D.

[0065] Subsequently, by e.g., test-operating the suction pump H, the perfusion condition of the perfusate C within the closed circuit will be confirmed. This completes the preparatory procedure of the apparatus.

[0066] Upon completion of the preparation of the intraocular surgical apparatus A described above, the closing plug will be removed from the leading end of the handpiece 3 and the inlet opening 1 a of the introduction tube 1 of the handpiece 3 and the aspiration opening 2A of the discharge tube 2 will be inserted into the closed intraocular affected part B through a small incision made in the cornea.

[0067] Then, as illustrated in FIG. 2, ultrasonic waves will be applied to the affected part such as the crystalline lens for gradually emulsifying it and at the same time, the emulsified part will be aspirated and discharged to the outside under the suction force from the suction pump H. In the course of this, the switch valve F incorporated within the perfusate feed passage D will be opened in response to the activation of the suction pump H, so that an amount of new perfusate C corresponding to the amount used and discharged will be fed into the introduction tube 1 into the intraocular affected part B, thus balancing the perfusion amount and the suction pressure with each other. In this normal condition, there is no problem of passage resistance, so that the supplementary perfusate reservoir J1 and the gas reservoir J2 of the pressure-reduction compensating means J are being maintained under equilibrium so as to hold the supplementary perfusate C1 retained within the tube 8 portion forming the supplementary perfusate reservoir J1. Accordingly, in this condition, the perfusate C will be perfused from the perfusate reservoir E into the intraocular affected part B.

[0068] Whereas, as illustrated in FIG. 3, in the event of abnormal pressure reduction in the closed intraocular affected part due to momentary clogging of the affected part at e.g., the aspiration opening 2A of the discharge tube 2 and subsequent sudden release and movement thereof toward the discharging side, in response to and in operative association with this phenomenon, the compressed gas 10 reserved within the gas reservoir J2 will be expanded, thereby to cause the supplementary perfusate C1 present within the supplementary perfusate reservoir J1 to flow immediately in reverse from this reservoir J1 into the intraocular affected part B, whereby the balance between the perfusate rate and the suction pressure of the suction pump H may be maintained.

[0069] [Second Embodiment]

[0070] In the first embodiment described above, the handpiece 3 includes the ultrasonic wave generating means 4. However, in the case of treatment of cataract, if its core is not so hard (i.e., hardness of Grade 1 or so) it may be aspirated and discharged without using ultrasonic waves. Therefore, the present invention may be applied to an intraocular surgical apparatus not having or not using any ultrasonic wave generating means 4.

[0071] Specifically, the second embodiment relates to such intraocular surgical apparatus adapted for aspirating and discharging the affected portion directly from the closed intraocular affected part, without relying on the ultrasonic wave generating means 4 described and employed in the foregoing embodiment.

[0072] [Other Embodiments]

[0073] 1) In the foregoing embodiment, the gas reservoir J2 of the pressure-reduction compensating means J is charged with gas 10. Instead, this gas reservoir J2 of the pressure-reduction compensating means J can be charged with inert gas.

[0074] 2) In the foregoing embodiment, the pressure-reduction compensating means J includes the supplementary perfusate reservoir J1 for reserving the perfusate portion C1 and the gas reservoir J2 both formed within the tube 8 so as to be balanced with the predetermined rest liquid pressure (h) of the perfusate reservoir E. Instead, the pressure-reduction compensating means J can consist of the supplementary perfusate reservoir J1 formed within the tube 8 and a gas reservoir J2 also formed within the tube 8 in the form of a spherical dome.

[0075] 3) Also, the pressure-reduction compensating means J may comprise combination of the supplementary perfusate reservoir J1 and a diaphragm connected with this supplementary perfusate reservoir J1.

[0076] 4) In the foregoing embodiment, the switch valve F incorporated in the perfusate feed passage D is the ON/OFF type switch valve F which controls the flow rate of the perfusate depending on whether it is fully opened or fully closed. Instead, this valve can be a flow control valve capable of variably and continuously controlling the flow rate of the perfusate C.

[0077] 5) In the foregoing embodiment, the perfusate reservoir E is provided in the form of a single glass bottle or vial filled with the perfusate C prepared by dilution of appropriate drug solution with diluent, with the perfusate reservoir E being connected to the perfusate feed passage D. The present invention is not limited to this construction. Alternatively, a plurality of perfusate reservoirs E may be provided to be disposed at different altitudes from each other, with one of these reservoirs E being selectively connectable to the perfusate feed passage D via a switch valve associated therewith.

[0078] The present invention may be embodied in any other forms than described above. The present embodiments, therefore, should be construed in all respects to be illustrative only, not limiting the scope of the invention defined in the appended claims. Other modifications and changes will be apparent for those skilled in the art without departing from the scope of the claims. And, such modifications and changes too are intended to be encompassed within the appended claims. 

What is claimed is:
 1. An intraocular surgical apparatus comprising: an introduction tube for introducing perfusate into a closed intraocular affected part; a discharge tube for discharging the affected part together with the perfusate; a perfusate feed passage connected to the introduction tube, the perfusate feed passage incorporating a perfusate reservoir capable of feeding the perfusate with a predetermined rest liquid head pressure and a control valve for controlling the amount of perfusate to be fed from the perfusate reservoir to the introduction tube; a. discharge passage connected to the discharge tube, the discharge passage incorporating a suction pump; wherein the perfusate feed passage further incorporates, at a passage portion thereof from the control valve to an outlet opening of the introduction tube, a pressure-reduction compensating means capable of feeding a supplementary amount of perfusate into the closed intraocular affected part through a supplementing passage having a smaller passage resistance than the perfusate feed passage in the event of and in association with abnormal pressure reduction inside the affected part.
 2. The apparatus according to claim 1, wherein the pressure-reduction compensating means includes a supplementary perfusate reservoir storing a portion of the perfusate flowing within the perfusate feed passage and acting as the supplementing passage and a gas reservoir for reserving gas compressed under the predetermined rest liquid head pressure of the perfusate reservoir.
 3. The apparatus according to claim 1, wherein the introduction tube and the discharge tube are provided in a handpiece which includes an ultrasonic-wave generating means capable of applying ultrasonic waves in focus onto vicinity of the inlet opening of the discharge tube.
 4. The apparatus according to claim 2, wherein the perfusate feed passage is formed by a flexible tube, and the supplementary perfusate reservoir and the gas reservoir of the pressure-reduction compensating means are constructed in the form of a single flexible continuous tube.
 5. The apparatus according to claim 4, wherein the flexible tube constituting the supplementary perfusate reservoir and the gas reservoir of the pressure-reduction compensating means is made of silicone.
 6. The apparatus according to claim 4, wherein the tube constituting the supplementary perfusate reservoir and the gas reservoir of the pressure-reduction compensating means is provided at an upper end of the gas reservoir to be opened and closed by opening-closing means.
 7. The apparatus according to claim 4, wherein the tube constituting the supplementary perfusate reservoir and the gas reservoir of the pressure-reduction compensating means is detachably connected and communicated with the perfusate feed passage connected to the introduction tube.
 8. The apparatus according to claim 4, wherein the tube constituting be constituting the supplementary perfusate reservoir and the gas reservoir of the pressure-reduction compensating means has an inner diameter substantially equal to that of the tube constituting the perfusate feed passage.
 9. The apparatus according to claim 2, wherein the gas reservoir of the pressure-reduction compensating means is charged with inert gas. 